Micturating cystourethrogram as a tool for investigating UTI in children - An institutional audit

Micturating cystourethrograms (MCUG) are the gold standard for evaluating vesicoureteric reflux (VUR). There is a growing consensus for increasing the threshold for performing MCUGs following urinary tract infections (UTI) in children. There are several varying guidelines. It is important to detect high-grade reflux in the setting of an UTI because of potential long-term complications.

This audit aimed to retrospectively: (1) identify the conformance rate of local guidelines at the Women's and Children's Hospital (WCH); (2) assess predictors for an abnormal MCUG; and (3) compare local guidelines against the Royal Children's Hospital, Melbourne (RCH), National Institute for Healthcare and Excellence (NICE), and American Academy of Pediatrics (AAP) guidelines for selectively detecting high-grade reflux.

The number of MCUGs performed from 2008 to 2012 at the WCH radiology department was collected. Patients undergoing MCUG during the 2012 calendar year were identified. Only children having an initial MCUG as part of an UTI investigation with prerequisite imaging as per guidelines were included. Each child's age, sex, referral source, reason, renal ultrasound (RUS) prior to the MCUG, MCUG result and VUR grade were recorded. The WCH guidelines were applied to determine conformance, to evaluate predictors for an abnormal MCUG, and compared against other retrospectively applied guidelines (RCH, NICE, AAP).

There was complete data for 168 children who underwent MCUG as part of an UTI investigation (median age 0.79 years, range 0.12-8.74, male:female 67:101). There were 67/168 abnormal MCUGs (62 children with VUR, five bladder diverticulum), and 97 refluxing renal units (43 high-grade VUR units). No posterior urethral valves (PUV) were identified as part of the UTI investigation. A total of 143/168 patients had prior RUS (normal:abnormal 67:76). The WCH guidelines had 82% conformance. There was no statistically significant association between an abnormal MCUG and age, sex, referral source, reason, or prior RUS result. The WCH guidelines may have missed five children with high-grade VUR (four children had surgery), compared with RCH, APP and NICE, with 8, 15, and 17 children, respectively, having high-grade VUR (two, five, and five children had surgery, respectively) show in the Summary Table. The retrospective study had limitations and possible selection bias (children with UTI without a MCUG). There were no standard treatment approaches for VUR; hence establishing a MCUG guideline is difficult. An alternative is the top-down approach.

Current institutional guidelines for considering MCUG following UTI in children vary considerably. The MCUG guidelines at any institution must take into account the local management guidelines for high-grade VUR.